Traditionally, a wind turbine is stopped if ice is detected on the wind turbine blades or if there is a risk that there is ice on the blades, as ice breaking of the blades may fall off or may be thrown away from the blade and thus damage items or hurt humans.
However, if the wind turbine is erected in a closed area with no access or with controlled and monitored access, a certain amount of ice on the outer surface of the blades may be acceptable, if it can be assured that ice falling down from the blades or being thrown away form the blades cannot hit humans or fragile items outside the area or fragile items within the area.